1. Field of the Invention
The present invention relates to a semiconductor device which transmits and receives data by wireless communication. Further, the present invention relates to a semiconductor device which can prevent deterioration of element characteristics and destruction of the element of the semiconductor device in the case where the semiconductor device receives high power in wireless communication.
2. Description of the Related Art
In recent years, research and development on increasing power supply efficiency from a reader/writer to an RF tag has been actively conducted in order to expand a response range in wireless communication system.
In general, power decays in proportion to square of distance from a spot where power is emitted to an observation spot. That is, power to be applied to an RF tag is high as distance (hereinafter referred to as communication distance) between a reader/writer and the RF tag is short, and power to be applied to the RF tag is small as the communication distance is long.
Even in the case where power which can be received by an RF tag is small, such as the case where the communication distance is long, it is necessary to reduce power consumption of the RF tag as one of means of normal communication. In order to realize low power consumption of the RF tag, transistors which have been driven at a low voltage have been used in many cases.
On the other hand, even in the case where power which can be received by the RF tag is high, such as the case where the communication distance is short, research and development has been conducted for stable communication (e.g., Reference 1: Japanese Published Patent Application No. 2002-368647).